Modern microbiological research has increasingly focused on the interactions between bacterial cells and the surfaces that they inhabit. To this end, microfluidic devices have played a large role in enabling research of cell-surface interactions, especially surface attachment and biofilm formation. This review provides background on microfluidic devices and their use in biological systems, as well specific examples from current literature. Methods to observe and interrogate cells within microfluidic devices are described, as well as the analytical techniques that are used to collect these data.